How Viruses Work

week 3 ANATOMY: Diagram of Human Tissue. A tissue is made up of a group of cells that usually look similar to one another and come from the same region in a developing embryo. The group of cells that make up a tissue have physiological functions that work together in a coordinated way to support special functions. The special function of a tissue is also influenced by the kind of material that surrounds the tissue and by communication among the cells of the tissue.